From mboxrd@z Thu Jan 1 00:00:00 1970 From: Manivannan Sadhasivam Date: Tue, 01 Dec 2020 13:47:25 +0000 Subject: Re: [PATCH] bus: mhi: core: Fix error handling in mhi_register_controller() Message-Id: <20201201133525.GB9748@work> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Dan Carpenter Cc: Bhaumik Bhatt , Hemant Kumar , Greg Kroah-Hartman , Jeffrey Hugo , Siddartha Mohanadoss , Loic Poulain , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org On Tue, Dec 01, 2020 at 10:02:54AM +0300, Dan Carpenter wrote: > There are a few problems with the error handling in this function. They > mostly center around the alloc_ordered_workqueue() allocation. > 1) If that allocation fails or if the kcalloc() prior to it fails then > it leads to a NULL dereference when we call > destroy_workqueue(mhi_cntrl->hiprio_wq). > 2) The error code is not set. > 3) The "mhi_cntrl->mhi_cmd" allocation is not freed. > > The error handling was slightly confusing and I re-ordered it to be in > the exact mirror/reverse order of how things were allocated. I changed > the label names to say what the goto does instead of describing where > the goto comes from. > > Fixes: 8f7039787687 ("bus: mhi: core: Move to using high priority workqueue") > Signed-off-by: Dan Carpenter Good find... Thanks for the patch, Dan! Reviewed-by: Manivannan Sadhasivam Thanks, Mani > --- > drivers/bus/mhi/core/init.c | 29 ++++++++++++++--------------- > 1 file changed, 14 insertions(+), 15 deletions(-) > > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c > index 96cde9c0034c..f0697f433c2f 100644 > --- a/drivers/bus/mhi/core/init.c > +++ b/drivers/bus/mhi/core/init.c > @@ -871,7 +871,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > sizeof(*mhi_cntrl->mhi_cmd), GFP_KERNEL); > if (!mhi_cntrl->mhi_cmd) { > ret = -ENOMEM; > - goto error_alloc_cmd; > + goto err_free_event; > } > > INIT_LIST_HEAD(&mhi_cntrl->transition_list); > @@ -886,7 +886,8 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > ("mhi_hiprio_wq", WQ_MEM_RECLAIM | WQ_HIGHPRI); > if (!mhi_cntrl->hiprio_wq) { > dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate workqueue\n"); > - goto error_alloc_cmd; > + ret = -ENOMEM; > + goto err_free_cmd; > } > > mhi_cmd = mhi_cntrl->mhi_cmd; > @@ -932,7 +933,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > ret = mhi_read_reg(mhi_cntrl, mhi_cntrl->regs, > SOC_HW_VERSION_OFFS, &soc_info); > if (ret) > - goto error_alloc_dev; > + goto err_destroy_wq; > > mhi_cntrl->family_number = (soc_info & SOC_HW_VERSION_FAM_NUM_BMSK) >> > SOC_HW_VERSION_FAM_NUM_SHFT; > @@ -946,7 +947,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > mhi_cntrl->index = ida_alloc(&mhi_controller_ida, GFP_KERNEL); > if (mhi_cntrl->index < 0) { > ret = mhi_cntrl->index; > - goto error_ida_alloc; > + goto err_destroy_wq; > } > > /* Register controller with MHI bus */ > @@ -954,7 +955,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > if (IS_ERR(mhi_dev)) { > dev_err(mhi_cntrl->cntrl_dev, "Failed to allocate MHI device\n"); > ret = PTR_ERR(mhi_dev); > - goto error_alloc_dev; > + goto err_ida_free; > } > > mhi_dev->dev_type = MHI_DEVICE_CONTROLLER; > @@ -967,7 +968,7 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > > ret = device_add(&mhi_dev->dev); > if (ret) > - goto error_add_dev; > + goto err_release_dev; > > mhi_cntrl->mhi_dev = mhi_dev; > > @@ -975,19 +976,17 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl, > > return 0; > > -error_add_dev: > +err_release_dev: > put_device(&mhi_dev->dev); > - > -error_alloc_dev: > +err_ida_free: > ida_free(&mhi_controller_ida, mhi_cntrl->index); > - > -error_ida_alloc: > +err_destroy_wq: > + destroy_workqueue(mhi_cntrl->hiprio_wq); > +err_free_cmd: > kfree(mhi_cntrl->mhi_cmd); > - > -error_alloc_cmd: > - vfree(mhi_cntrl->mhi_chan); > +err_free_event: > kfree(mhi_cntrl->mhi_event); > - destroy_workqueue(mhi_cntrl->hiprio_wq); > + vfree(mhi_cntrl->mhi_chan); > > return ret; > } > -- > 2.29.2 >